This invention relates to an improved portable, self-contained, self-adjustable craft lift and wet/dry storage system and to an improved method for raising and lowering the system and for the wet/dry storing of such crafts.
The storage of crafts in water for prolonged periods of time results in substantial problems. First, marine growth, such as, algae, barnacles and the like inhibits maximum boat speed, particularly in the case of sailboats. It also results in long-term damage to the structural integrity of the craft since various chemicals present in the water cause deterioration of the hull and electrolysis of the metal components of the craft. Finally, any leakage problems are exacerbated by being stored in water for long periods of time.
Accordingly, boat lift/storage systems have been developed to alleviate the above-described problems. Most of these prior art systems are part of, or are attached to, a permanent dock. See U.S. Pat. Nos. 3,276,211, Re. 27,090, 3,727,415, 3,777,691, 3,857,248, 3,991,695, 3,967,570, 4,018,179, and 4,037,421. However, the above prior art lift/storage systems are expensive to build and are not readily transportable to another location, certainly not on a cost-effective basis.
Of the known prior art lift/storage systems, some include pontoons to provide buoyancy, such as U.S. Pat. Nos. 3,265,024, 4,027,492, and 4,072,119. However, in these latter cases, the frame itself remains in a fixed position with respect to the pontoons during the raising/lowering operations and does not coact with the lifting mechanism. In addition, the lifting-structural support means required to operate these systems are complex and costly.
The structural framework portion of the above prior art support systems typically have a rectangular cross-sectional configuration which does not conform to the shape of the boat hull. This non-conformity makes it difficult at best for boat self-adjustment, i.e., lateral alignment and/or leveling of the boat within the confines of the system's structural framework. In U.S. Pat. Nos. 3,857,248, 3,991,695, 3,967,570, 4,027,492, and 4,072,119, respectively, rigid, fixed boat hull support elements are provided in an attempt to overcome the self-adjustment problem and to assist in the performance of the boat aligning and leveling operations. However, these support elements are fixed, and they do not readily adjust and conform to the shape of the boat. Instead, these elements require substantial supplemental mechanical adjustment in order to provide structural conformity between the elements and the hull. Therefore, significant alignment and leveling problems still remain unresolved.
Other unresolved problems not recognized by the prior art include boat storage related to seasonal and/or tidal conditions as they affect wet/dry storage, partial lifting of a boat for repair purposes and the lift/storage of deep keel boats.
During the winter season, many bodies of water become frozen due to extremely cold temperatures. It would be desirable to have a storage system which could support a craft on the frozen surface or could also be employed to bring such craft onto shore for storage on the frozen terrain. Furthermore, tidal variations occur which result in the waterline receding to the point where a craft runs aground. Under these latter circumstances, it would also be desirable for a craft storage system to have the ability to be stored both on a body of water or on the bottom when low tide occurs.
Lifting of an entire boat out of the water in order to make certain types of repairs can be a problem. Raising/lowering of either front or back portions of a boat expedites such repairs since a portion of a larger boat can be raised by a given lifting apparatus.
Many sailboats have deep keels. Due to their extended keel size, the requisite clearance does not exist between the keel and the system framework for supporting that sailboat thereon. There is no prior art system designed to affect deep keel storage.